DFT + Study of the Adsorption and Dissociation of Water on Clean, Defective, and Oxygen-Covered USi{001}, {110}, and {111} Surfaces.

The interfacial interaction of USi with water leads to corrosion of nuclear fuels, which affects various processes in the nuclear fuel cycle. However, the mechanism and molecular-level insights into the early oxidation process of USi surfaces in the presence of water and oxygen are not fully understood. In this work, we present Hubbard-corrected density functional theory (DFT + ) calculations of the adsorption behavior of water on the low Miller indices of the pristine and defective surfaces as well as water dissociation and accompanied H formation mechanisms.

Atomistic and experimental study on thermal conductivity of bulk and porous cerium dioxide.

Cerium dioxide (CeO) is a surrogate material for traditional nuclear fuels and an essential material for a wide variety of industrial applications both in its bulk and nanometer length scale. Despite this fact, the underlying physics of thermal conductivity (k), a crucial design parameter in industrial applications, has not received enough attention. In this article, a systematic investigation of the phonon transport properties was performed using ab initio calculations unified with the Boltzmann transport equation.

Oxidation behaviour of USi: an experimental and first principles investigation.

Uranium-containing metallic systems such as USi are potential Accident Tolerant Fuels (ATFs) for Light Water Reactors (LWRs) and the next generation of nuclear reactors. Their oxidation behaviour, especially in oxygen and water-enriched environments, plays a critical role in determining their applicability in commercial reactors. In this work, we have investigated the oxidation behaviour of USi experimentally and by theoretical computation.

A molecular dynamics simulation of the diffusion of the solute (Au) and the self-diffusion of the solvent (Cu) in a very dilute liquid Cu-Au solution.

The identification of the manner in which a solute diffusion coefficient (D) might vary with temperature (T) in a fused metal or semimetal has led to considerable experimental study and some theoretical analysis. However, the conclusions of this work are inconsistent. In the present work, molecular dynamics studies of diffusion of a very dilute solute (Au) in liquid Cu are presented.

Solute diffusion in nonionic liquids--effects of gravity.

We have been engaged in examining the influence of gravity on the results of experiments to measure the variation of solute diffusion coefficients (D) with temperature (T) in fused metals and semimetals since our first STS flights in 1992. These early experiments, conducted with the in situ g-jitter of the shuttle, showed the near-parabolic variation of D with T reported by others. However, with the aid of the Canadian Space Agency's microgravity isolation mount (MIM) to isolate the diffusion facility from the existing g-jitter of the Russian space station MIR, we showed that in all the alloy systems and over the temperature range studied, D increased linearly with T.